The fate of chromium in a simple, laminar diffusion flame will be studied in the first phase of the project. The oxidation state of the chromium aerosol that is formed in the flame will be determined as a function of the flame temperature and residence time. The impact of chlorine on the fate of the chromium will be tested in this inhomogeneous system. The possible inclusion of chromium into soot particles that are emitted from the flame will also be evaluated by collecting soot above a flame that is seeded with chromium. The health impact of the gas phase and particulate phase materials that are emitted from the flames will be investigated in collaboration with groups using various bioassays. The thermal remediation group will also collaborate with biologists in developing and testing a continuous, "on-line" bio-sensor for monitoring the postflame gases from simple laboratory combustion systems with chlorinated hydrocarbons and chromium. Attention in the second stage of the project will be directed towards the evaluation of relatively novel, commercial thermal treatment systems that have a possible application to soil venting operations at sites such as the Mare Island Naval Ship Yard near San Francisco. The two technologies that will be tested are a heated ceramic bed and a catalytic system. Both operate at lower temperatures than incinerators. They are not well tested under varying conditions of chlorine loading and possible metal contamination. A simple experimental model will be developed for the heated ceramic bed and catalytic systems viz., a stagnation point flow against a flat surface. Measurements of species and temperatures will elucidate the nature of the oxidation process in these technologies, especially with vapor composition that varies with time as found during soil venting operations. Conditions that may lead to health hazards will be evaluated. Lead may be found in sites that are contaminated with leaded gasoline. The impact of lead vapor on the operation of the thermal and catalytic treatment methods will be evaluated. The fate of the lead will be determined..